Communication networks are known to include a plurality of communication switches interoperably coupled to provide communication links between end users. Such end users are coupled to the communication network via ports associated with the plurality of switches. The users may be individual users such as personal computers, telephones, videophones, facsimile machines, etc. The users may also be other network components such as servers, routers, private branch exchanges (PBX), etc. The communication network may also include a network manager that manages the establishment of communication links and overall operation of the communication system.
As is known, to establish a communication path between ports of different switches communication links between the endpoint switches and intervening switches need to be established. As is also known, each port within a switch may support multiple communications between users that traverse the same path over one or more links. The communications supported in the network may be virtual connections (VCs), which are also referred to as virtual circuits and which may include virtual path connections (VPCs) and virtual channel connections (VCCs). Each individual virtual connection is identified by a virtual connection identifier (VCI). In order to reduce the amount of state information required to be maintained by intervening switches, paths of the multiple communications supported by a single port may be aggregated to form a virtual path aggregation. Within the virtual path aggregation, each of the virtual connections maintains its own unique identity through the use of its VCI. As such, at the terminating end of the virtual path (VP) aggregation, each of the individual virtual connections (VCs) can be reconstructed based on the VCI included within each cell.
Another technique that enables multiple virtual connections to traverse the network in a simplified manner is accomplished through virtual connection merging. When a virtual connection merge operation is performed, multiple virtual connections are combined into a single virtual connection that has a single unique virtual connection identifier that corresponds to the merged virtual connection. As such, the individual cells carried across the merged virtual connection do not include the VCIs that identify them as corresponding to a particular virtual connection that has been merged into the merged virtual connection. As such, the cells within a particular packet for a virtual connection must be sent in a sequential manner such that no intermingling of cells from different packets corresponding to different virtual connections occurs.
Because the bandwidth available for transporting data within a merged virtual connection is limited, there are numerous issues that arise regarding prioritization of data transmission such that different qualities and classes of service may be supported. Therefore, a need exists for a method and apparatus that supports virtual connection merging and allows for prioritization of available bandwidth.